The MAA was signed in 1969 by Canada and the governments of Alberta, Saskatchewan, and Manitoba in recognition of the need to cooperatively share and manage interprovincial waters for the benefit of present and future generations.

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Goal 3: Achieve Water Quality Objectives

What are the PPWB Objectives?

To encourage the protection and restoration of interprovincial streams, the Agreement on Water Quality (Schedule E) includes a set of PPWB Water Quality Objectives. The benefit of the PPWB objectives is to promote cooperative water quality management and protection of major eastward flowing rivers that cross the borders of the three Prairie Provinces. They are guidelines which the Board uses to determine whether the water in a particular river is acceptable. The objectives also help in assessing the impact of proposed developments on water quality and enable the PPWB to identify potential interprovincial water quality issues.

The PPWB objectives were developed using provincial objectives or, where available, basin specific objectives. If these objectives were not available, then the surface water guidelines of the Canadian Council of the Ministers of the Environment (CCME) were used. All water uses were considered, and the PPWB adopted the most conservative water quality objective to give the highest level of protection to the aquatic ecosystem.

The PPWB objectives are specific to each transboundary river reach. Environment and Climate Change Canada has monitored water quality monthly on eastward flowing interprovincial rivers since 1974. The information gathered indicates that river quality is influenced by several factors. These include land uses within the basin, various biological and chemical processes, groundwater infiltration and municipal and industrial effluent. Consequently, water quality is unique for each river. Given these variations and the different needs the water serves, the PPWB objectives were developed to reflect the characteristics of each river system.

The PPWB objectives are considered appropriate and acceptable for each of the 12 major interprovincial eastward flowing river reaches (Water Quality Monitoring Locations and Objectives). Six of these reaches are along the Alberta-Saskatchewan border and six are along the Saskatchewan-Manitoba border. Other streams can be added as required.

Schedule E states that objectives should be reviewed from time to time to ensure that they reflect current water uses, priorities of member agencies and the latest technological information. New interprovincial water quality objectives and new objectives were ratified in July 2015. There are now 71 objectives for water quality parameters, including nutrients, metals, major ions, physical characteristics, pesticides and radioisotopes.

How are the PPWB Objectives Applied?

The PPWB reports comparisons of interprovincial water quality monitoring results with the objectives. These comparisons are done on samples taken throughout the calendar year and are reported each year in the PPWB's Annual Report. If monitoring indicates an objective is not being met, the Committee on Water Quality (COWQ) - a permanent committee of the PPWB - will investigate to determine the cause, and whether there is a risk to downstream water uses. The committee will closely study the cause of the condition and decide whether it is a one-time or a long-term event. If the event indicates a water quality issue, then COWQ will prepare a report to the Board, with an explanation and a recommended course of action.

The board will consider COWQ's report and may make recommendations to the upstream province in which the event occurred. The appropriate agency then takes whatever corrective action is required.

To complement the comparisons of PPWB objectives, COWQ also carefully examines long-term data derived from water samples collected near provincial borders. Subtle changes or trends in the samples, when occurring over a long time, may indicate an impending drop in water quality before the objective is actually exceeded. This advance knowledge enables the appropriate agencies to take corrective steps before the change in water quality becomes a problem.

Through the comparisons with objectives and trends analysis, the PPWB promotes a philosophy for protecting and improving water quality in interprovincial streams. The PPWB member agencies agree that in cases where water is better than the objective, they will endeavour to maintain the existing water quality. Where the objective is better than the existing water quality because of human activities, reasonable and practical measures will be taken to improve the quality to meet the objective.